Method and apparatus for the operation of a concentrator for the schweretruebe a floating link - processing plant for coal or ores

摘要

Volatile liquid nitric esters of monohydric aliphatic alcohols are purified substantially from nitrous ester by washing the nitric ester with an excess of an aqueous solution containing urea and a mineral acid in a concetration to cause evolution of gas in the presence of the urea only as long as the nitrous ester is present, and thereafter freeing the nitric ester substantially from said acid and excess urea. The washing with urea and mineral acid is preferably conducted at about 40 DEG C. and is preferably preceded by a washing with water. The mineral acid is preferably nitric acid and the concentration of the aqueous solution in contact with the alkyl nitrate is preferably between 1 and 3 Normal. The urea and mineral acid are preferably employed in the form of the urea salt of the acid, e.g. urea nitrate, a saturated solution thereof being employed. The examples describe the purification of ethyl, isopropyl and secondary butyl nitrate.